Effects Of Chemical Control Agents On Physiological Characteristics And Yield Of Summer Maize Under High Temperature Stress

In view of the problem that summer maize was prone to high temperature disasters and resulted in lower yield of maize in hebei province.It was necessary to clarify the regulation effect of chemical control agents on photosynthetic physiological characteristics and grain yield of summer maize under high temperature stress.Xianyu 335 and nongda 372 were used as material,in xinji test stationnin of hebei agricultural university,from June to October in 2018.The experiment was conducted in plastic greenhouses,from ninth lamina leaf to silking stage.during high temperature simulation.2-ethyl phosphonic acid,chloride in 9 spraying on the leaf stage poly(aspartic acid and amino acid,contrast with spraying water in the corn 5 spraying on the leaf stage.The effect of chemical control agent on agronomic traits,photosynthetic physiological characteristics and yield of summer maize was study.The main research results were as follows:1.Plant height and panicle height of xianyu 335 and nongda 372 were significantly reduced after spraying chemical control agents(2-chloroethylphosphonic acid,poly aspartic acid and amino acid),and the internode length and stem diameter were not significantly difference.The plant heights of xianyu 335 was reduced by 11.65%,2.81% and 44.20%,respectively,when 2-chloroethylphosphonic acid,poly aspartic acid and amino acid were sprayed.Nongda 372 decreased by 13.50%,16.04% and 28.37%,respectively.2.Spraying 2-chloroethylphosphonic acid,poly aspartic acid and amino acid of leaves can reduce the adverse effects of high temperature in maize.At 40 d after silking,the leaf area of xianyu 335 and nongda 372 increased significantly after polyaspartic acid treatment.The net photosynthetic rates of xianyu 335 and nongda 372 of amino acids were the highest.Compared with the control with water,the SPAD of leaves in xianyu 335 increased by 19.29% and 16.66%,respectively after the treatment of poly aspartic acid and amino acid,whereas Nongda 372 increased by 8.56% and 6.51%.When nongda 372 was sprayed with 2-chloroethylphosphonic acid,it was 3.13% lower than that of water treatment.3.The superoxide dismutase activity in leaves of xianyu 335 increased after spraying chemical control agents(2-chloroethylphosphonic acid,polyaspartic acid and amino acid),but the difference was not significance in nongda 372.The application of poly(aspartic acid)increased the activity of peroxidase in leaves of two cultivars.At the spinning stage,the activity of peroxidase in leaves of xianyu 335 increased by 14.96%,75.81% and 37.83%.Nongda increased its 372 by 15.17%,47.09% and 10.93%,respectively.The malondialdehyde content in leaves of two cultivars could be reduced by spraying 2-chloroethylphosphonic acid and poly(aspartate)amino acids.From the above research results,the conclusion of this study is that,spraying poly(aspartic acid)can improve the leaf area and net photosynthetic rate of maize,increase the activity of antioxidant enzyme in leaves,and reduce the content of malondialdehyde in leaves,and then improving the grain yield of maize.Spraying poly aspartic acid can be popularized to achieve higher and stable yield of maize under high temperature disaster.